Some of you might have been aware that I've been having fuel pump issues with the pump in the rear tank(87 F250 460 carbed). Called Carter Tech line, the rep gave me a way of testing the circuit. Using a sealed beam headlight(3 prong), connect it so both high and low beams will come on. Hook it to the battery to observe the brightness. Now go to the pump plug in and hook it to the + and - at the plug. Observe the brightness. If the brightness is the same as battery voltage, usually ground and hot connections are ok. If not than you might have either ground or hot connection problems. Rep. said this light set up draws about 8 amps which is what the Carter pumps draw.

On the downside, my truck circuit checked out ok. Have to check further.

 

Interesting. I have always used a multimeter when checking for voltage.

Although I did set the RPMS on a portable generator by using a trouble light with a 100 watt bulb once.

Robert